Abstract: Effects of sowing time on dry matter content of the super high-yield ratoon rice were studied with the two-line hybrid rice Liangyoupeijiu.The results indicated that early sowing and planting resulted in(a)prolonged growth period for the main rice,but shortened for the ratoon rice,(b)prolonged peak tillering stage for the main rice,(c)increased tiller number in main rice,and(d)hastened grain dry weight increase for the main rice-rapid increase occurred from 6d to 25d after sprouting.On the other hand,late sowing and planting caused slower grain dry weight increase in the main rice.The yield of early sowed and planted main rice increased by 7.18%-9.56%,and for the ratoon rice increased by 53.47%.